Biomarkers for irritable bowel syndrome

Abstract

The present invention relates to a method of determining the probability that an individual has irritable bowel syndrome and whether the individual will respond to dietary intervention. The present invention also provides a method of determining the probability that an individual with irritable bowel syndrome will respond to dietary intervention. There is also provided the use of a compound as defined herein as a biomarker.

The invention claimed is: 
     
       1. A method of determining the probability that an individual has irritable bowel syndrome and whether the individual will respond to dietary intervention, the method comprising the steps of:
 i) analysing a stool sample collected from said individual to determine whether a cyclohexane carboxylic acid compound is present; and 
 ii) if a cyclohexane carboxylic acid compound is present in step i), determining the amount of the cyclohexane carboxylic acid compound that is present and comparing the amount detected with a control value; 
 wherein the presence of an increased amount of the cyclohexane carboxylic acid compound compared to the control value is indicative of an increased probability that the individual has irritable bowel syndrome and of the probability that the individual will respond to dietary intervention; and wherein the cyclohexane carboxylic acid compound is one or more of a cyclohexane carboxylic acid and/or a cyclohexane carboxylic acid ester. 
 
     
     
       2. The method according to  claim 1 , wherein the cyclohexane carboxylic acid compound is cyclohexane carboxylic acid and/or a cyclohexane carboxylic acid (1-4C) alkyl ester. 
     
     
       3. The method according to  claim 1 , wherein the cyclohexane carboxylic acid compound is selected from cyclohexane carboxylic acid methyl ester, cyclohexane carboxylic acid ethyl ester, cyclohexane carboxylic acid propyl ester, and cyclohexane carboxylic acid butyl ester. 
     
     
       4. The method according to  claim 3 , wherein the cyclohexane carboxylic acid compound is selected from cyclohexane carboxylic acid ethyl ester, cyclohexane carboxylic acid propyl ester and cyclohexane carboxylic acid butyl ester. 
     
     
       5. The method according to  claim 1 , wherein the step of analysing the stool sample involves detecting whether two or more cyclohexane carboxylic acid compound are present. 
     
     
       6. The method according to  claim 1 , wherein the presence and amount of the cyclohexane carboxylic acid compound is determined by detecting volatile organic compounds emanating from the stool sample using gas chromatography mass spectrometry (GC-MS). 
     
     
       7. The method according to  claim 1 , wherein the individual has one or more symptoms associated with irritable bowel syndrome. 
     
     
       8. The method according to  claim 7 , wherein the one or more symptoms associated with irritable bowel syndrome are selected from, diarrhoea, constipation, abdominal cramps and abdominal pain. 
     
     
       9. The method according to  claim 1 , wherein the dietary intervention is a low wheat diet. 
     
     
       10. The method according to  claim 1 , wherein the dietary intervention is a low FODMAP diet. 
     
     
       11. A method of determining the probability that an individual with irritable bowel syndrome will respond to dietary intervention, the method comprising the steps of:
 i) analysing a stool sample collected from said individual to determine whether a cyclohexane carboxylic acid compound is present; and 
 ii) if a cyclohexane carboxylic acid compound is present in step i), determining the amount of the cyclohexane carboxylic acid compound that is present and comparing the amount detected with a control value; 
 wherein the presence of an increased amount of the cyclohexane carboxylic acid compound compared to the control value is indicative of an increased probability that the individual will respond to dietary intervention; and wherein the cyclohexane carboxylic acid compound is one or more of a cyclohexane carboxylic acid and/or a cyclohexane carboxylic acid ester. 
 
     
     
       12. The method according to  claim 11 , wherein the cyclohexane carboxylic acid compound is cyclohexane carboxylic acid and/or a cyclohexane carboxylic acid (1-4C) alkyl ester. 
     
     
       13. The method according to  claim 11 , wherein the cyclohexane carboxylic acid compound is selected from cyclohexane carboxylic acid methyl ester, cyclohexane carboxylic acid ethyl ester, cyclohexane carboxylic acid propyl ester, and cyclohexane carboxylic acid butyl ester. 
     
     
       14. The method according to  claim 13 , wherein the cyclohexane carboxylic acid compound is selected from cyclohexane carboxylic acid ethyl ester, cyclohexane carboxylic acid propyl ester and cyclohexane carboxylic acid butyl ester. 
     
     
       15. The method according to  claim 11 , wherein the step of analysing the stool sample involves detecting whether two or more cyclohexane carboxylic acid compound are present. 
     
     
       16. The method according to  claim 11 , wherein the presence and amount of the cyclohexane carboxylic acid compound is determined by detecting volatile organic compounds emanating from the stool sample using gas chromatography mass spectrometry (GC-MS). 
     
     
       17. The method according to  claim 11 , wherein the individual has one or more symptoms associated with irritable bowel syndrome. 
     
     
       18. The method according to  claim 17 , wherein the one or more symptoms associated with irritable bowel syndrome are selected from, diarrhoea, constipation, abdominal cramps and abdominal pain. 
     
     
       19. The method according to  claim 11 , wherein the dietary intervention is a low wheat diet. 
     
     
       20. The method according to  claim 1 , wherein the dietary intervention is a low FODMAP diet.